1. Field of the Invention
The present invention relates to a method for controlling a direct current chopper controller which has at least one current channel with each current channel having a storage choke and semiconductor switches which are controllable by a micro-controller.
2. Background Art
DE 10 2007 041 510 describes a direct current (“DC”) chopper controller which may operate either as a step-up converter or a step-down converter. The controller includes multiple current channels each including a storage choke and semiconductor switches. A micro-controller is operable to control the switches. The controller is operated at the edge of the gap (i.e., in the transition-mode) as switching losses of the switches are minimal here under full-load operation. The drop in the coil current in one of the current channels to zero value is sensed in order to again switch the current channels displaced in phase with respect to one another. In each cycle, the storage chokes are fully magnetized. At small currents, the switching frequency of the switches can become quite large. The losses thereby increase strongly because of magnetic reversal in the storage chokes and/or switching losses in the switches whereby the efficiency is lowered in the partial-load region.